I am using WLP037 Yorkshire Square Ale. I stepped up one vial this week. I boiled it in a 2 L flask and cooled it and decanted it into a 5 L flask and cooled it. I was decanting it and noticed a sour smell. It tastes very slightly sour, but it is a yeast starter. I wonder if I should use it or not? I have never tasted a starter before, so I don't know if this is normal or not. This is the only yeast I have on hand.

I'm assuming you didn't boil your yeast...

If the starter wort both smelled and tasted slightly sour, then I would not use it. Is it just a "yeasty" smell and tang, or does it truly have a sour note to it? You could always try adding some additional starter wort to it (after decanting the old) and see if that too comes out sour like the first one, just to be sure.

What was your best by date on your yeast? Since that was a while ago in the platinum series...

Apr 2 2012. I tossed the starter. It took me all week to step up. Pissed me off. Next time I step up some yeast, I'll go with the larger flask and stick with it.

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